Merge branch 'master' of git://git.denx.de/u-boot-arm

Kbuild

@@ -53,7 +53,8 @@ targets += arch/$(ARCH)/lib/asm-offsets.s
 
 # Default sed regexp - multiline due to syntax constraints
 define sed-y
-	"/^->/{s:->#\(.*\):/* \1 */:; \
+	"s:[[:space:]]*\.ascii[[:space:]]*\"\(.*\)\":\1:; \
+	/^->/{s:->#\(.*\):/* \1 */:; \
 	s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
 	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
 	s:->::; p;}"

Makefile

@@ -197,8 +197,8 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 	  else if [ -x /bin/bash ]; then echo /bin/bash; \
 	  else echo sh; fi ; fi)
 
-HOSTCC       = gcc
-HOSTCXX      = g++
+HOSTCC       = cc
+HOSTCXX      = c++
 HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
 HOSTCXXFLAGS = -O2
 

arch/arm/include/asm/global_data.h

@@ -44,10 +44,35 @@ struct arch_global_data {
 
 #include <asm-generic/global_data.h>
 
+#ifdef __clang__
+
+#define DECLARE_GLOBAL_DATA_PTR
+#define gd	get_gd()
+
+static inline gd_t *get_gd(void)
+{
+	gd_t *gd_ptr;
+
+#ifdef CONFIG_ARM64
+	/*
+	 * Make will already error that reserving x18 is not supported at the
+	 * time of writing, clang: error: unknown argument: '-ffixed-x18'
+	 */
+	__asm__ volatile("mov %0, x18\n" : "=r" (gd_ptr));
+#else
+	__asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr));
+#endif
+
+	return gd_ptr;
+}
+
+#else
+
 #ifdef CONFIG_ARM64
 #define DECLARE_GLOBAL_DATA_PTR		register volatile gd_t *gd asm ("x18")
 #else
 #define DECLARE_GLOBAL_DATA_PTR		register volatile gd_t *gd asm ("r9")
 #endif
+#endif
 
 #endif /* __ASM_GBL_DATA_H */

arch/arm/lib/eabi_compat.c

@@ -20,8 +20,19 @@ int raise (int signum)
 /* Dummy function to avoid linker complaints */
 void __aeabi_unwind_cpp_pr0(void)
 {
-};
+}
 
 void __aeabi_unwind_cpp_pr1(void)
 {
-};
+}
+
+/* Copy memory like memcpy, but no return value required.  */
+void __aeabi_memcpy(void *dest, const void *src, size_t n)
+{
+	(void) memcpy(dest, src, n);
+}
+
+void __aeabi_memset(void *dest, size_t n, int c)
+{
+	(void) memset(dest, c, n);
+}

arch/arm/lib/spl.c

@@ -28,9 +28,6 @@ void __weak board_init_f(ulong dummy)
 	/* Clear the BSS. */
 	memset(__bss_start, 0, __bss_end - __bss_start);
 
-	/* Set global data pointer. */
-	gd = &gdata;
-
 	board_init_r(NULL, 0);
 }
 

arch/arm/lib/vectors.S

@@ -45,12 +45,13 @@
  *************************************************************************
  */
 
+_start:
+
 #ifdef CONFIG_SYS_DV_NOR_BOOT_CFG
 	.word	CONFIG_SYS_DV_NOR_BOOT_CFG
 #endif
 
-_start:
-	ldr	pc, _reset
+	b	reset
 	ldr	pc, _undefined_instruction
 	ldr	pc, _software_interrupt
 	ldr	pc, _prefetch_abort
@@ -77,7 +78,6 @@ _start:
 	.globl	_irq
 	.globl	_fiq
 
-_reset:			.word reset
 _undefined_instruction:	.word undefined_instruction
 _software_interrupt:	.word software_interrupt
 _prefetch_abort:	.word prefetch_abort

common/board_r.c

@@ -912,7 +912,7 @@ void board_init_r(gd_t *new_gd, ulong dest_addr)
 	int i;
 #endif
 
-#ifndef CONFIG_X86
+#if !defined(CONFIG_X86) && !defined(CONFIG_ARM) && !defined(CONFIG_ARM64)
 	gd = new_gd;
 #endif
 

doc/README.clang

@@ -0,0 +1,56 @@
+The biggest problem when trying to compile U-boot with clang is that
+almost all archs rely on storing gd in a global register and clang user
+manual states: "clang does not support global register variables; this
+is unlikely to be implemented soon because it requires additional LLVM
+backend support."
+
+Since version 3.4 the ARM backend can be instructed to leave r9 alone.
+Global registers themselves are not supported so some inline assembly is
+used to get its value. This does lead to larger code then strictly
+necessary, but at least works.
+
+NOTE: target compilation only work for _some_ ARM boards at the moment.
+Also Aarch64 is not supported: Most notably boards which aren't using
+the generic board will fail to compile, but since those are expected
+to be converted this will solve itself. Boards which reassign gd in c
+will also fail to compile, but there is in no strict reason to do so
+in the ARM world, since crt0.S takes care of this. These assignments
+can be avoided by changing the init calls but this is not in mainline yet.
+
+NOTE: without the -mllvm -arm-use-movt=0 flags u-boot will compile
+fine, but llvm might hardcode addresses in movw / movt pairs, which
+cannot be relocated and u-boot will fail at runtime.
+
+Debian (based)
+--------------
+Binary packages can be installed as usual, e.g.:
+sudo apt-get install clang
+
+To compile U-Boot with clang on linux without IAS use e.g.:
+export TRIPLET=arm-linux-gnueabi && export CROSS_COMPILE="$TRIPLET-"
+make HOSTCC=clang CC="clang -target $TRIPLET -mllvm -arm-use-movt=0 -no-integrated-as" rpi_b_defconfig
+make HOSTCC=clang CC="clang -target $TRIPLET -mllvm -arm-use-movt=0 -no-integrated-as" all V=1 -j8
+
+FreeBSD 11 (Current):
+--------------------
+Since llvm 3.4 is currently in the base system, the integrated as is
+incapable of building U-Boot. Therefore gas from devel/arm-eabi-binutils
+is used instead. It needs a symlinks to be picked up correctly though:
+
+ln -s /usr/local/bin/arm-eabi-as /usr/bin/arm-freebsd-eabi-as
+
+# The following commands compile U-Boot using the clang xdev toolchain.
+# NOTE: CROSS_COMPILE and target differ on purpose!
+export CROSS_COMPILE=arm-eabi-
+gmake CC="clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0" rpi_b_defconfig
+gmake CC="clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0" -j8
+
+Given that u-boot will default to gcc, above commands can be
+simplified with a simple wrapper script, listed below.
+
+/usr/local/bin/arm-eabi-gcc
+---
+#!/bin/sh
+
+exec clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0 "$@"
+

include/linux/kbuild.h

@@ -7,14 +7,14 @@
 #define __LINUX_KBUILD_H
 
 #define DEFINE(sym, val) \
-	asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+	asm volatile("\n.ascii \"->" #sym " %0 " #val "\"" : : "i" (val))
 
-#define BLANK() asm volatile("\n->" : : )
+#define BLANK() asm volatile("\n.ascii \"->\"" : : )
 
 #define OFFSET(sym, str, mem) \
 	DEFINE(sym, offsetof(struct str, mem))
 
 #define COMMENT(x) \
-	asm volatile("\n->#" x)
+	asm volatile("\n.ascii \"->#" x "\"")
 
 #endif

scripts/Kbuild.include

@@ -113,12 +113,12 @@ as-instr = $(call try-run,\
 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 
 cc-option = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
 
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 cc-option-yn = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 
 # cc-option-align
 # Prefix align with either -falign or -malign